The Study On Growth And Electrooptic Character Of High Quality DKDP Crystal

In this thesis ,the stability of the growing solution ,the influence of the purity of solution and growth rate on the quality of DKDP crystals ,and the concrete technique of DKDP crystal growth were studied . What's more , the electro-optic character of DKDP crystals was introduced ,and the electro-optic apparatus ----Pockel's cell was designed and made .The growing solution of DKDP crystal was synthesized firstly,then the source and possible introducing method of impurities were discussed by the measurement of metal ion impurity concentrations.By studying the influence of different filtration ,supersaturation, saturation temperature on solution stability,We gained the results as follows: superfiltration can decrease the concentration of unsolvable impurity ,finally the number of molecule cluster and the probability of nucleation in the solution should be decreased . Stability of the solution decreased with the increasing of the supersaturation and saturate temperature of the growing solution .Some DKDP single crystals have been grown by traditional temperature falling method on the Z-cut point seed (4mm×4mm×3mm) in DKDP metastable crystal phase district. The high quality DKDP crystal's growth conditions are obtained : In glass crystallizer of 1000ml in volume the growth rates reach to 3.8mm/day in the [100] direction ,the temperature falling speedis 0.3-2℃/day,the growth temperature range is 43-23℃ and the pD=4.0-4.2 .The DKDP crystal with dimensions of 44mm×44mm×48mm was successfully grown with the growth rate of 4.1 mm/day in glass crystallizer of 2300ml in volume. The growth mechanism of DKDP crystal was observed and described . The growth of regeneration process of point seed was observed and the mechanism was explained . Some factors which can influence the quality of crystal were analyzed , such as purity of solution ,growth rate and flow form .The results showed that the quality of crystals have little relationship with growth rate, but were deteriorated with the decreasing of the purity of solution .The possible reason of crystals quality decreased with increasing of growth rate in low purity solution were analyzed . Crystals grown from high purity solution with different growth rates have good quality . Their laser damage threshold ,half-wave voltage, extinction ratio are about 5GW/cm2(1064nm), 4Kv(632nm) ,and 1600:1(632nm). Course of the formation of some common defects were analyzed ,and some effective measure which can resolve those problems were discussed .At last ,Pockel's cell were made with the high quality DKDP crystal.